Ever so often, I get asked questions from doctors, and I figure that here is a reasonable place to put how I answer the frequently asked ones. Â As with everything I write, it’s my opinion, and doctors opinions vary.
One question I get asked a lot is how to prescribe clomiphene for a male. Â Here’s how I do it.
First, clomiphene works by stimulating the pituitary. Â If the pituitary’s already in overdrive, clomiphene won’t help. Â So if a man’s LH is high, like 25 IU/L, I don’t prescribe clomiphene.
The next decision to make is what the target for therapy will be. Â If it’s augmenting a low testosterone level, then I’ll use the bioavailable testosterone calculation described in a previous post. Â AsÂ a reasonable threshold for total testosterone is 300 ng/dL and the portion of bioavailable testosterone ranges betweenÂ 52% and 70%,1 I use the range between 156 ng/dL to 210 ng/dL as a lower limit of what is likely an adequate bioavailable testosterone level for a man. Â If the target for clomiphene therapy is stimulating the testis to make sperm, I use a higher threshold. Â If possible we try for twice as much, about 400 ng/dL for bioavailable and 600 ng/dl for total testosterone. Â It’s not always possible to achieve those levels.
I start with 25 mg clomiphene a day. Â As the pills come in 50 mg, and the half-life is relatively long, patients can take a pill every other day. Â Some prefer talking half a 50 mg pill daily. Â After two weeks, I have the patient get tests for testosterone, LH, albumin, SHBG (sex hormone binding globulin) and estradiol. Â In some instances, the estradiol will increase, but as long as the ratio of total testosterone to estradiol is greater than ten-to-one, that shouldn’t be a problem. Â If the estradiol increases substantially, other therapy, like an aromatase inhibitor, is preferred. Â If the testosterone is still low, then we’ll increase the clomiphene by 25 mg every other day or daily, and repeat the tests. Â I’ll increase the clomiphene to a maximum of 100 mg daily.
I believe that clomiphene works better if a man’s testosterone is low. Â That’s a good indication that there is a problem that may be corrected. Â If the testosterone is reasonable at the start, 400 ng/dL or more, then pushing it higher may not be as effective. Â But that’s my opinion, and as of present, scientific studies don’t definitively prove it right or wrong.
It’s important to note that clomiphene is “off-label” for use in the male. Â I explain this in a previous post.
1S. Bhasin. Chapter 18: Testicular disorders. Â In: Kronenberg H. M., Melmed S., Polonsky K. S., and Reed Larsen P., eds. Williams Textbook of Endocrinology 11th ed. Philadelphia, W.B. Saunders Company, 2008; 647.